The CoGeNT Collaboration has reported evidence of an annual modulation in its first 15 months of data. Here we compare the amplitude and phase of this signal to the modulation observed by the DAMA Collaboration, assuming that both arise due to elastically scattering dark matter (DM). We directly map the CoGeNT signal to the DAMA detector without specifying any astrophysical parameters and compare this with the signal measured by DAMA. We also compare with constraints from CDMS II and XENON10. We find that DM of mass 5–14 GeV that couples equally to protons and neutrons is strongly disfavored. Isospin-violating DM fares better but requires a boosted modulation fraction.

• Received 12 July 2011

DOI:https://doi.org/10.1103/PhysRevD.84.043525